The present invention is directed, in general, to wireless communications systems and, more specifically, to apparatus or methods to route information from a packet-switched network to a mobile device communicating with a wireless telecommunications network.
The world is currently experiencing revolutionary changes in communication systems, brought about by the general availability of access to the Internet as well as wireless telephony. In particular, interest in Internet Protocol (IP) telephony, or Voice over IP (VoIP), has expanded rapidly as the associated technologies have matured. Interoperability is a prominent factor in the success of Internet telephony. The creation of the International Telecommunications Union (ITU) Recommendation H.323 is one step to ensure such interoperability.
Recommendation H.323 describes the technical requirements for multimedia communications services in a packet-switched network, such as the communication of audio, video and data over the conventional Internet. Packet-switched networks, however, may also include private and public local area networks (LANs), wide-area networks (WANs), and point-to-point dial-up connections over point-to-point protocol (PPP) or other packet-switched protocols. The advent of IP telephony allowing phone calls across packet-switched networks triggered a revolution in the telecommunications industry. Early IP telephony, however, had many limitations that prevented it from becoming a mainstream telephony service. One of the biggest problems was a lack of connectivity between an IP telephony network and the public switched telephone network (PSTN). This led to the development of a gateway that allows IP and PSTN customers to communicate with each other; such communications, however, have conventionally required the routing of information between IP and PSTN customers through the circuit-switched network of the PSTN.
The telecommunications industry has also recently undergone a revolution in the area of wireless telephony; e.g., xe2x80x9ccellularxe2x80x9d or xe2x80x9cmobilexe2x80x9d devices. Wireless telecommunications networks are an adjunct to the PSTN, and depend upon the circuit-switched network of the PSTN for communications with conventional wired telephony devices as well as with mobile devices. Thus, the routing of information to a mobile device communicating with a wireless telecommunications network has heretofore also required all such information to be routed through the PSTN.
Because of the proliferation of IP telephony and mobile devices, there is a need in the art for apparatus, methods and systems for efficiently routing information from a packet-switched network to a mobile device communicating with a wireless telecommunications network. Because both IP telephony and mobile devices currently depend upon the circuit-switched network of the PSTN, even greater demand will be placed on the PSTN as IP telephony and mobile device capabilities and services continue to expand. Accordingly, there is a particular need in the art for apparatus, methods and systems for routing information between IP telephony and mobile devices that do not require use of the circuit-switched network of the PSTN.
To address the above-discussed deficiencies of the prior art, the present invention relates to apparatus, methods and systems for routing information from a packet-switched network to a mobile device communicating with a wireless telecommunications network. In one embodiment of a wireless telecommunications system employing the principles of the invention, a call request for a mobile device is received from the packet-switched network at a first node of the wireless telecommunications network; a determination is made of the serving node of the wireless telecommunications network in communication with the mobile device and whether the serving node is coupled to the packet-switched. network; and the call request is redirected to the serving node in response to an affirmative indication that the serving node is coupled to the packet-switched network. Alternatively, if the serving node is not coupled to the packet-switched network, the call request is routed from the first node to the serving node through a circuit-switched network coupled intermediate to the first node and the serving node.
In various embodiments, the determination of the serving node of the wireless telecommunications network in communication with the mobile device is accomplished by (i) sending an inquiry to a location resource of the wireless telecommunications network, wherein the inquiry includes a unique identifier of the mobile device, such as the Mobile Station Integrated Service Digital Network (MSISDN) number identifying the mobile subscriber or device; and (ii) querying a database in the location resource using the unique identifier, wherein the database includes an association between the unique identifier and the serving node of the wireless telecommunications network in communication with the mobile device.
Once the serving node of the wireless communications network in communication with the mobile device has been identified, it is then determined whether that serving node is coupled to the packet-switched network. In one embodiment, the inquiry sent to the location resource includes an indicator that the call request for the mobile device is from the packet-switched network. The location resource then sends a request for routing information to the serving node of the wireless telecommunications network in communication with the mobile device; the request for routing information includes an indicator that the call request for the mobile device is from the packet-switched network. The serving node then transmits a response to the request for routing information to the location resource; the response includes the unique address of the serving node on the wireless telecommunications network. The response also includes an address of the serving node on the packet-switched network if it is coupled to that network. If the serving node is coupled to the packet-switched network, the call request is redirected to the serving node. Alternatively, if the serving node is not coupled to the packet-switched network, the call request is routed from the first node to the serving node through the circuit-switched network coupled intermediate to the first node and the serving node.
In an alternate embodiment, conventional signaling can be employed between the first node, location resource and serving node to return the unique address of the serving node on the wireless telecommunications network to the first node. The determination of whether the serving node is coupled to the packet-switched network is then accomplished by querying a database using the unique address of the serving node on the wireless telecommunications network; the query returns an address of the serving node on the packet-switched network if the database identifies that the serving node is coupled to the packet-switched network. If the serving node is coupled to the packet-switched network, the call request is redirected to the address of the serving node on the packet-switched network. Alternatively, if the serving node is not coupled to the packet-switched network, the call request is routed from the first node to the serving node through the circuit-switched network coupled intermediate to the first node and the serving node.
The principles of the present invention may be employed to advantage in combinations of various packet-switched and wireless communication network topologies. The packet-switched network may be, for example, the Internet and the circuit-switched network may be the Public Switched Telephone Network (PSTN), whereby calls originating from devices coupled to the Internet, or similar network, can be directly routed to a serving node of the wireless telecommunications network in communication with the mobile device or, if the serving node is not coupled to the Internet, such calls can be routed through the PSTN. If the packet-switched network is the Internet, the address of the serving node is preferably an Internet Protocol (IP) address; as used herein, xe2x80x9cIP addressxe2x80x9d is defined to include a basic IP address, a xe2x80x9csocket,xe2x80x9d which comprises an IP address plus a port number, and an IP address plus any other data used to identify a transaction or process associated with the IP address. If the present invention is employed in a conventional Public Land Mobile Network (PLMN), the first node of the wireless telecommunications network can be a Gateway Mobile-Services Switching Center (GMSC), the serving node of the wireless telecommunications network in communication with the mobile device can be a Mobile-Services Switching Center (MSC), and the location resource can be a Home Location Register (HLR). Those skilled in the art will readily conceive of other packet-switched and wireless communication network topologies that may advantageously employ the principles of the invention; such applications of the invention are intended to be within the scope of the claims recited hereinafter.
As described more fully hereinafter, the present invention provides various apparatus, methods and systems for routing information from a packet-switched network to a mobile device communicating with a wireless telecommunications network. Instead of always routing such information through a circuit-switched network associated with the wireless telecommunications network, the present invention redirects a call request for a mobile device to the serving node of the wireless communications network in communication with the mobile device if the serving node is coupled to the packet-switched network, thereby bypassing the circuit-switched network.
The foregoing has outlined, rather broadly, the principles of the present invention so that those skilled in the art may better understand the detailed description of the exemplary embodiments that follow. Those skilled in the art should appreciate that they can readily use the disclosed conception and exemplary embodiments as a basis for designing or modifying other structures and methods for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form, as delimited by the claims recited hereinafter.